Not sure how... but this car got wedged under a large truck on a California highway and was dragged 4-miles.  The driver of the car tried to get the attention of the truck driver but it took other drivers on the freeway to finally get the truck to stop.

Luckily, no one was hurt.  The truck driver claimed he didn't know he was dragging a car. 

HOW DO YOU NOT KNOW THAT?

This is something you definitely don't see every day.